在Django 2.0中过滤外键

Question

So I need to filter posts, posted by users, who the user currently logged in is following.

Here's my models:

class ProfileDetails(models.Model):
    user = models.ForeignKey(User, on_delete=models.CASCADE, null=True)
    provider = models.CharField(max_length=20, null=True, blank=True)
    firstname = models.CharField(max_length=25, null=True, blank=True)
    lastname = models.CharField(max_length=25, null=True, blank=True)
    username = models.CharField(max_length=24, null=True, blank=True, unique=True)

    def __str__(self):
        return str(self.user)


class Posts(models.Model):
    post_id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    user = models.ForeignKey(ProfileDetails, on_delete=models.CASCADE, null=True)
    text = models.TextField(max_length=280, null=True, blank=True)
    video = models.CharField(max_length=24, null=True, blank=True)
    timestamp = models.DateTimeField(default=datetime.datetime.now, blank=True)

    def __str__(self):
        return str(self.user)


class Connection(models.Model):
    follower = models.ForeignKey(ProfileDetails, related_name='follower', on_delete=models.SET_NULL, null=True)
    following = models.ForeignKey(ProfileDetails, related_name='following', on_delete=models.SET_NULL, null=True)
    # follower = models.ManyToManyField(ProfileDetails, related_name='follower')
    # following = models.ManyToManyField(ProfileDetails, related_name='following')
    date_created = models.DateTimeField(auto_now_add=True, null=True)

    def __str__(self):
        return str(self.follower)

And then in my views, my bit of Python / Django knowledge kind of directed me to write something like this (take a look particularly at the last bit, where I try to filter it so it only gets details from the users I follow.

def index(request):
    checkuser = request.user
    print(checkuser)
if ProfileDetails.objects.filter(user=checkuser):
            print("user previously logged in")
            sns = get_object_or_404(SocialAccount, user=checkuser)
            autoupdateprofile = get_object_or_404(ProfileDetails, user=checkuser)
            autoupdateprofile.lastlogin = datetime.datetime.now()
            autoupdateprofile.save(update_fields=["lastlogin"])

            # print(sns.provider)

            details = get_object_or_404(ProfileDetails, user=checkuser)
            videos = Posts.objects.filter(media=True, imade=True).order_by("-timestamp")[0:6]
            followercount = Connection.objects.filter(follower=details).count()
            follows = Connection.objects.filter(follower=details)

            followerposts = Posts.objects.filter(user=follows)



            for a in followerposts:

                print(a)

return render (request, 'index.html', context)

However, this doesn't seem to work. I'm greeted with this lovely error trying to get me to use the data from the model ProfileDetails - which would obviously make no sense, cause how else can I indicate the users I'm following in Connections.

Exception Value:    
Cannot use QuerySet for "Connection": Use a QuerySet for "ProfileDetails".

Been struggling with this for a few days and no longer sure what to search for.

If it makes any difference, I'm using Python 3.6 and Django 2.0.4 on Postgresql.

Suggestions would be appreciated. :)

Thanks in advance. Ronald

Answer 1

该代码进入并从当前用户关注的用户（即当前用户为其follower ）获取所有帖子：

Posts.objects.filter(user__following__follower=ProfileDetails.objects.get(user=self.request.user))